


Flu, Fears, & Fellswap Sans

by ReadWithDetermination



Series: When Two Tsunderes Go on A Date, Does the Void Implode? [4]
Category: Undertale (Video Game)
Genre: Alphys and Undyne ship it, Angst and Humor, Awkward Crush, Comedy of Errors, Confused Sans (Undertale), Death by Disease (mentioned), Epidemics (mentioned), Established Alphys/Undyne (Undertale), Eye Trauma (Toriel's blindness briefly mentioned), F/M, Fellswap - Freeform, Fellswap AU - Freeform, Fellswap Asgore Dreemurr, Fellswap Papyrus - Freeform, Fluff and Angst, Fluff and Hurt/Comfort, Heartwarming, Influenza, M/M, Matter of Life and Death (or so Sans thinks), Mild Language, Misunderstandings, Not Actually Unrequited Love, Not Really Character Death, One Tsundere Nursing Another Tsundere Back to Health, Papyrus and Nameless Nurse are Best Bros, Papyrus ships it, Post-Undertale Pacifist Route, Sick Character, Sickfic, Slice of Life, Tsundere Reader, Tsundere Sans (Undertale), Undertale Monsters on the Surface, fellswap sans - Freeform, genderless reader
Language: English
Status: Completed
Published: 2019-12-03
Updated: 2019-12-04
Packaged: 2021-02-26 04:13:40
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 8,785
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21657343
Author URL: https://archiveofourown.org/users/ReadWithDetermination/pseuds/ReadWithDetermination
Summary: Precursor to "Matchmaker Papyrus and his Two Tsunderes", and follows "The Sans Situation".(FellSwap/Swapfell Red Sans & Papyrus Surface AU)Sans may have bucked up the courage to tell his brother how he felt about you, but that didn't mean he was ready to be so direct with YOU.  However, when your roommate informs him that you are sick, he almost lets his emotions get the better of him.
Relationships: Alphys/Undyne (mentioned), Asgore Dreemurr/Toriel (Past), Sans/Reader
Series: When Two Tsunderes Go on A Date, Does the Void Implode? [4]
Series URL: https://archiveofourown.org/series/1558828
Comments: 28
Kudos: 110





	1. CHAPTER ONE - "The Misunderstanding"

**Author's Note:**

  * For [Chaoswithtea](https://archiveofourown.org/users/Chaoswithtea/gifts).



> It was supposed to be a one-shot. How did I wind up with a series?  
> For that matter, how did this one-shot of a one-shot become a chaptered fic?  
> Who knows! But I'm on a roll now! XD
> 
> A minor warning for talks about historical epidemics, death by influenza, and why Toriel is blind in this version of Fellswap.  
> I am by no means saying the flu isn't deadly; I actually had a former classmate pass away early last year due to complications from the flu.  
> However, as we have already established, I have the biggest soft spot for misunderstandings that lead to comedies of errors.  
> (I lmao every time I see a rendition of "Something Funny Happened on the Way to the Forum", if that gives you any idea.)
> 
> Alright, enjoy!

**CHAPTER 1 - "The Misunderstanding"**  
\-----------------------------------------

Sans did it.

He finally bucked up the courage and told his brother how he felt about you.

Papyrus took the news very well, even if he did tease Sans about his "feelings". He refused to acknowledge the word "crush". No, such a term was far too plebeian a term to describe the emotional depth of the Great and Malevolent Sans!

Besides, his feelings went far deeper than that, though he refused to reveal just how much to his brother. He hated to say it, but being around you made him feel like he'd gone soft. 

Until that point, the only person in Sans' life that he held any sort of affection for was Papyrus, and look how that turned out. He'd admitted it during one of Papyrus' group sessions, as a way to atone for his sins and help with his brother's healing. He had to be an ass to his brother to try to keep him from being targeted, to make him seem more like a victim of having to share the same magical DNA as his heinous elder brother, but Sans knew he had overstepped the boundaries between necessary tough love and undeserved cruelty many times. There were times Sans was cruel to Papyrus because he was angry. Angry at the fact that any day, he would stumble upon a black-and-yellow hoodie, unable to tell what was dust and what was snow. Anger helped him power through his grief, staved away the sadness because it was harder to be sad when another intense emotion was flowing through him. He'd tried to desensitize himself to the inevitability of being alone by making Papyrus hate him - by trying to convince himself that he hated Papyrus — but that was short-lived. He immensely regretted hurting his brother and vowed to do anything in his power to help Papyrus heal from the ordeal.

But some feelings, he found, are just as powerful as anger.

Oh, he could keep it condensed to a smirk most times, but there were times the usual predatory grin he had perfected over the years almost gave way to the softer, fonder true smile he barely concealed underneath. He was able to mask it with excuses: winning a match, successfully throwing you off your game, making you drop your card hand, etc. The times when you were in the middle of a physical challenge or he was sparring with Alphys were the best, for he could really tap into the extra burst of energy your presence filled him with and unleash it freely.

Alphys actually had been the one to call him out on it, first.

The yellow saurian monster had been his tentative ally Underground, being the closest thing he had to a friend besides Muffet. That being said, the two of them knew the day might come when one might have to turn on the other - be it by the Blind Queen's orders, to save their loved ones, or to prevent all-out genocidal anarchy should a riot backing one of the other ever occur. Sans knew Alphys had not taught him everything she knew because of that, and Sans never allowed her to see his full power in case he needed an ace up his sleeve. Once they settled into life on the Surface, however, the bitter chains binding them had broken, and Alphys had truly become like the scaly sister he never had.

She, like Sans, knew what she wanted and went after it. However, while she was fine to dive headlong into a relationship with Undyne even in the Underground, Sans held back. Perhaps it was his age or inexperience, or maybe even his having to mask his true emotions in a way that Alphys with her wild and feral persona did not, but he found himself stopping short of revealing his feelings to you beyond playful (albeit rough) touches and backhanded compliments.

Alphys knew something was up the day he brought out the Gaster Blasters and cut a 300-yard crossroads into the woodlands behind her house right after you showed up.

Of course, she figured it out. Alphys had known him for years and could read many of his tells almost as well as Papyrus. She also knew from personal experience how having Undyne's eyes on her from the sidelines made her as giddy as a schoolgirl inside. Instead of bouncing around, squeeing and cuddling her battleaxe from the overwhelming affection she felt for her fishy girlfriend, she channeled her feelings into showing how incredibly powerful she truly was.

She saw the exact same thing the moment Sans pulled it on her.

And she immediately told Undyne.

There were few things he missed about the Underground, but Alphys not being an outspoken batshit-bonkers fangirl and the self-proclaimed leader of the Sans/You Fanclub was one of them.

For the Angel's sake, they had wrote FANFICTION about the two of you! Did you have any idea how awkward it was to hear the closest thing he had to a best friend and her girlfriend talk about the scenarios they had wrote you two in?! He still felt his skull burn the day Undyne showed up with a binder of her more...ahem..."risque" stories. One excerpt from that was enough; two excerpts had him vaporize the whole thing. When the shock of nearly getting dusted had worn off, Undyne had simply grinned and chuckled, claiming that the binder only held copies, and that the originals were still locked up tight where Sans could never get to them.

(Not that he didn't try, mind you, but the Seek and Destroy mission he had gone on had resulted in him being able to stare at the files but unable to touch them, as Undyne had them programmed to send straight to you from a spoofed email address to make them seem as if Sans had written them SHOULD the folder they were in and the computer they were on were not opened with their series of complex protection measures every 24 hours. Sans promptly mailed her a bottle of tartar sauce after that. She responded with a flyer for adoption prices at the local animal shelter and laughed in his face the next time she saw him.)

Despite their pestering, Sans was appreciative of the couple's support. Undyne might have had her problems, but if someone was important to Alphys, she would move mountains for them. When she learned of Sans concern about the nurse introducing Papyrus to a human they new as an ideal part of his support network, Undyne had cracked her knuckles and got to work running an extensive background check on you. She had shown up with the folder, reading off your (squeaky-clean) background history, even tossing in a few trivia facts she'd gleaned by hacking your social media before tossing the paper thin folder into Sans' lap. As it turned out, you shared the same interest in the same anime as both monster ladies, and Alphys immediately took a liking to your favorite sports team, so they were both cool with you.

Alphys goaded him to tell you how he felt before someone else snatched you up, but Sans just couldn't. No, instead, he got the brilliant idea to make you come to him! He'd show off how strong and smart and clever he was first. Every challenge the two of you set gave him an out to do so, all while you unknowingly ticked off each box in his standards for a good romantic partner. If the Great and Malevolent Sans could get you to see just how high he rose above all of the other figurative fish in the sea, then you would surely soon throw yourself into his arms and beg to be his!

Of course, it might have helped if you could actually see past the thinly veiled insults he covered his sincere compliments with, or see that he only riled you up just to have an excuse to be near and occasionally make physical contact with you without giving away his true intentions (and, okay, maybe he thought your literally getting hopping mad was adorable, too). But because you never took the hints, Sans simply tried different tactics, hoping you would figure out the puzzle of his feelings so he wouldn't have to tell you.

The thought of you rejecting him...wasn't one he liked to think about.

You were kind enough that you might still be friends with him, but the idea of you _knowing_ the true reason behind his challenges and not reciprocating his feelings hurt. He wouldn't be able to continue the little light love taps or playful pushes that gave him a chance to touch you. He secretly basked in the feeling of your warm flesh connecting with the bone of his upper arms, or the feel of your body colliding with his whenever you asked him to teach you a thing or two about fighting. To know that was unwanted meant you might deprive him of that deeply desired contact - or worse, be disgusted he ever wanted it in the first place.

The thought of your warmth and heart being shared with anyone else in the way he felt about you might drive him mad.

He wanted more but dared not risk changing things they way they were now. He would rather only imagine what could be than ever take the chance on losing you—

"Hey! Come on in."

Sans heard his brother's voice and turned to see the nurse he had befriended from the clinic — your roommate. He didn't realize he was holding his breath until he saw the door close behind them without you appearing, and if his shoulders slightly slumped, then that was neither here nor there.

In their hands were a couple of styrofoam food containers. "I thought you might like Korean barbecue," they told Papyrus. "I made sure to order Sans' with a bit more spice."

Sans surreptitiously glanced out the window, hoping you were just running behind. When he didn't see you, he frowned, and then turned to see your roommate trying to teach Papyrus to eat with chopsticks (and failing).

"And where is your roommate today?" Sans asked, hoping they were just late. 

As your roommate handed him his own carton, they frowned. "I was actually about to head home to check on them," they said. "I guess Papyrus didn't tell you?"

Sans glanced to his brother, and then back to the nurse. "No, I suppose not."

He heard Papyrus apologize and the nurse continued. "The only reason I'm here instead of at work is because they're sick. I didn't feel right about leaving them home alone when they have the flu. I haven't taken any personal days at work in a while, so I had a few saved up. Since I was headed home and knew you guys would be home, I brought—"

Sans held up a hand. "Did you just say they were ill?"

The nurse nodded. "Yeah."

Sans gulped. "With the flu? That is influenza, am I correct?"

They nodded again. "Yeah, that's right—"

"AND YOU LEFT THEM ALONE?!"

Sans did not normally give into his emotions, save for what he desperately tried to mask around you outside certain circumstances, but he couldn't help the bone-chattering bellow that tore out of him then. It was a tone he often mimicked without the venom when he used to train lower-ranked guards or to scare off wimpy opponents. Now, the deep octave and volume he'd only used with monsters that had gravely overstepped their boundaries and had driven him to dustlust literally shook the room, sending several framed paintings on the wall crashing to the floor as his magic flared up. The nurse quickly moved back and Papyrus, in a rare burst of energy, was in front of him with one of his own eyelights flaring a golden orange.

"Brother, calm down!"

"THEY WERE LEFT ALONE, PAPYRUS!" Sans continued to shout. "WITH INFLUENZA!!!"

He'd heard enough about this human disease. Monsters hardly ever got sick, and their version of monster flu was never so dangerous as that of humans. Sans had heard stories of the days before monsters were exiled Underground, and how entire villages were sometimes wiped out by epidemics of the flu. Not even two days prior, he had been watching the news and heard about how "Flu Season", as the television reporter had dubbed the wretched scourge, had already sent forty-eight people in their town to the hospital. Three of them had died.

"Where are they, human?" he snapped at the nurse, his volume lowering but his voice growing darker, deadlier.

"They're at home-"

Sans immediately fled to the kitchen, yanking open the pantry and grabbing the picnic basket on the bottom shelf. Ignoring the confused questions of his human friend, he took out his phone and found the contact he was looking for, then turned his attention to the shelves. It wasn't long before a deep yet chipper voice rumbled throught he receiver.

" _Well, howdy, Sans! To what do I owe the pleasure of this phone call?_ "

"Asgore," Sans breathed out, "I need your help. It's urgent."

The goat monster on the other end of the phone said a few hushed words to someone in the background, then came back onto the speaker, far more serious than before. " _What is wrong? Is it Papyrus?_ "

"No, it's..."

Sans told Asgore what the nurse had told him, trying to keep his voice from wavering. Such a thing was beneath the Great and Malevolent Sans, after all. So, too, was begging. But if the former king happened to read too much into what was said in his hushed tones, then who was to say that Asgore did not have a good imagination?

"I owe them a great deal for helping Papyrus-" 

( _I care about them._ )

"-and I would be greatly remiss in my duties as a brother and an ally-"

( _They are so dear to me._ )

"-if I stood by and did nothing-"

( _I don't want to lose them._ )

"-so while you have no duty of friendship toward me, for my brother's sake-"

( _I CAN'T lose them._ )

"-Asgore, will you come and help heal his friend?"

( _...I WILL NOT ALLOW IT!_ )

Sans heard more speaking in the background, a female voice if he heard correctly. A few others joined in, and he recognized a childish pitch of Chara. Asgore must have had Chara's parents over for visitation. Sans would have felt bad for interrupting had the situation been anything less dire.

" _...Sans?_ "

By the stars! Sans' eye sockets widened and he sank to one knee out of instinct upon recognizing the voice. 

"My Queen!" he said solemnly. Now he felt the guilt crawling up his back. Toriel had only just recently begun to get back in touch with Asgore, so their relationship was so very tentative. The Queen of the Underground had long been considered a terrifying despot who ruled with an iron fist, her ancient decree for monsters to grow stronger by doing whatever (including horrible) means necessary to one day take to the Surface and rage war against the humans who trapped them beneath the mountain and stole her child's life from her. 

Her true rage had abated long before Sans was even born, and by the time she realized how she had corrupted the Underground in her grief, she was too late to stop it. Few ever saw her before breaching the Surface, choosing to go through intermediaries than risk being on the receiving end of her legendary power. However, he had learned from Undyne that, powerful though she may still be, the once terrifying queen was now just a sad childless monster, blinded by her own hand in retribution for being unable to save her children. As a former member of the Royal Guard, he understood why Toriel would punish herself thus - honor, after all, was the only romanticized ideal held in the hellish caverns below. But to take her own sight so that the last thing she ever saw was the stripe-clad bodies of those she failed? Sans could not imagine such a horror.

" _Sans, I know you are kneeling. Please rise,_ " Thoroughly chastised, Sans did as commanded. " _You know that I am no longer Queen nor your employer. You need not address me so formally. I am merely Toriel._ "

"You will never be 'merely' anything, Your Ma-Pardon, Toriel," Sans said, "and I sincerely apologize for interrupting your visit with Asgore."

" _You need not apologize_ ," came the calm and matronly voice. " _Now tell me, where does this human friend of yours live? I will accompany Asgore and assist you in any way I can._ "

No one, not even the Great and Malevolent Sans, would deny being brought to tears at being granted a personal boon by the former Queen of all Monsters. Especially not when that boon also came in the form of one of the greatest healers monsterkind had ever known Underground. Sans wiped the trickle of red magic trickling down from his eye sockets and profusely thanked Toriel and Asgore, immediately giving them the address.

Asgore took over the call once more, " _Sans? Asgore here. We are currently in the middle of a visitation with Chara's parents. According to the location you have given us, we should arrive roughly five hours from now, plus time allowing for traffic._ "

Sans thanked the goat monsters again, asked them to pass his and Papyrus' greetings along to Chara, and then questioned them on what goods he might have on hand that would help stabilize you in the meantime. Upon Asgore's instructions, he took down several tins of tea (he was only told to take one or two, but Sans nearly emptied their stock), a few cartons of various soup stocks, and a whole box of crackers. He then went to the fridge and pulled out a large unopened bottle of ginger ale. The nurse had been quite adamant that you have that (as well as the crackers and broths) on hand should Chara ever get sick when they visited. He now was very thankful for their advice.

Right, he should probably apologize for being so rude to them since their preparation had helped somewhat.

He ended the call and turned to see Papyrus and your roommate standing in the entrance to the kitchen, the nurse still holding the container of food they brought especially for Sans.

"Sans?" the nurse asked tentatively. "What are you doing?"

Sans hefted the basket and pulled himself up to his full height. "I apologize for my volume earlier. You are the reason I have these human healing items on hand that Asgore recommended."

Papyrus and your roommate shared a look, and the tall skeleton crossed his arms. "Asgore?" he asked. "Is that who you were talking to so quietly? What did he want? We needing to babysit Chara?"

"I called him," Sans informed his brother, "and he will be on his way in a few hours. The Quee-Toriel, she is with him, and she will be coming, too."

"What, here?" Papyrus asked.

"No, to their house," Sans said, nodding toward the nurse. The human's eyes nearly bugged out of their sockets.

"Why did you call the king and queen?! And why are you sending them to my house? Don't you know that I have a sick person there?!"

"That is exactly why I called Asgore." 

Sans then explained that, while he had some limited use of green magic, something as powerful as a human disease required a skilled healer. The Dreemurrs were some of the few monsters who had lived on the Surface twice, and thus remembered the epidemics of old. As two of the most powerful healers known to monsterkind, if anyone could save his favorite human (not that he called them that in front of everyone), they could.

Before the nurse could say another word, Sans strode past them.

"Wha-? Where are you going?"

"You said someone needs to be with them, so that person shall be me." He hefted the basket of goods Asgore told him to bring and, not bothering to even take the car, disappeared as if he had never been there.

——————————————————————-

Meanwhile, stunned in his wake, a flummoxed nurse still stood with a container of Korean barbecue in their hands.

After a long moment of silence, Papyrus looked down at them.

"I thought you said they were almost better?"

"They _ARE!_ " the nurse shouted. "They've literally been on antibiotics for the past three days and have done nothing but sleep and drink power drinks! They just like being pampered while they're sick, so I was going to make them some soup so we could rewatch 'Mew Mew Kissy Cutie' together! I took the whole day off for it, too!"

Papyrus watched your roommate's shoulders slump as they stared at the container in their hands before sadly sauntering into the kitchen to put it away. The moment they pushed the dish into the fridge, however, a look of shock crossed their face. Papyrus moved the drinking straw he had been chewing on to the side so he could talk.

"What's with that look?"

"Oh, this is so good..." They took out their phone and immediately began texting.

"What is?"

The nurse glanced up from their phone with a smirk of a child who just stole a cookie. "Who does my roommate have a crush on?"

"Sans."

"And who, in a panic, just ported over to take care of them?"

Papyrus opened his mouth, but then started to chuckle. "You're right," he said, "that is good." The nurse cackled with maniacal glee as the finished their text. "So, since you have the day off, why don't you hang out over here while Sans dotes on his 'dearly _bone_ loved? Alphys just loaned us a series called 'Cosmic Railway'. It has that old style you like."

The nurse grinned.


	2. CHAPTER TWO - "Visiting the Infirm"

**Summary for the Chapter:**

> Sans visits you and tries to help, only find find out human bodies are weird and the healing items Asgore sent him with don't always help.

**Notes for the Chapter:**

> A bit short, but I wanted some more comedy before we got into the more heartwarming fluff. Gotta ease you all into that sort of thing so you don't die from cuteness overload, you know?

**CHAPTER TWO - "Visting the Infirm"**  
—————————————————————————————————————

Sans chose to teleport directly to your house rather than waste time driving. 

As he felt his magic dispel, he saw the gray-flecked white-and-yellow tile pattern of your kitchen floor appear beneath his feet. He had pranked you a few times before by porting into your house to set up a prank or to give you a good jumpscare, but he stopped doing that the day he appeared right in front of your roommate — who was clad only in a towel after getting out of the shower. After taking a good punch to the face (they had quite a mean right hook) and a well-aimed boot to the head (he was pleasantly surprised you could throw something so bulky with such precision), he had promised the two of you he would never pop into the house unannounced again unless it was an absolute emergency.

Your being stricken with the flu, however, was more than enough to warrant the intrusion.

However, he didn't want to scare someone who was in such a feeble state, so he unlocked the kitchen door and went through the motions of letting it slam shut. 

A groggy groan came from the living room. You croaked out your roommate's name.

"-Is that you? You're back early...Ack!"

He felt his soul wrench at the sound of a series of coughs ripping themselves from you. It took everything in his power not to run to you and force as much green magic into your system as he could muster, but he willed himself to remain firm. Asgore and Toriel would surely be better at it, so he would have to be careful he didn't overdo it until then. After all, he was far better at magics meant for the battlefield, and while he could heal minor ailments, magic he didn't have practiced control over took more of his strength than usual. He needed to assist you, to remain vigilant by your side until they arrived, and he couldn't do that if he was lying face-down on the floor, drained of magic.

He sat the basket onto the counter island and braced himself for what he was about to see.

You were on the sofa, sprawled out beneath several throw blankets and what looked to be a homemade quilt. A trashcan was placed nearby, and the long coffee table in front of you held a tray of various medicine bottles, a nearly empty package of saltines, and a wide array of empty sports drink and clear soda bottles. Several boxes of tissues, their soft papers standing at attention, were arranged nearby, as was the TV remote and a couple of books.

He looked as you raised your arm, waving your arm toward him without looking over the plush pillow that blocked his view of your person.

"Could ya' bring me a drink?" you asked. "I hate to ask, but as you can see, I've kinda run aground."

A weak chuckle followed the reference to your favorite pirate movie, and you waved your hand to indicate the empty bottles that had collected on the coffee table. You obviously did not see him, still thinking he was the nurse, but he did not correct you. Instead, he slipped back into the kitchen and put a kettle onto the stove to boil before pouring you a glass of the ginger ale he had brought with him.

When he walked into the living room, he saw you holding up your phone, reading a text. A split second later, you shot up, turning to him with wild, scared eyes.

Stars, you looked awful!

He had never seen you that pale before, nor how tired your eyes looked. Your skin no longer had the healthy sheen to it that it normally did, but now had dried skin flaking around your nose and reddened cracks around the corners of your mouth. You also had a slightly pinched look to your cheeks, as if you had not been eating properly.

You look so, so tired.

Sitting up so fast had made you woozy, and he saw you grasp your forehead and groan as you laid back down, whining a "Why me?" into your pillow. Sans walked over to you as you lolled your head back, craning it up just enough to give him the weakest stink-eye he had ever seen. It almost made him laugh at how cute your attempt to be obstinate even at Death's doorstep was.

"You look pathetic," he said, softening his smirk for once. You groaned and feebly swiped at him, as if trying to slap him, but the blow clearly had no power behind it. He chuckled. "Are you trying to fan me and give me the flu, too?"

"Fuck off," you said, rolling away from him.

Sans grabbed your shoulder and gently turned you back toward him. You rolled back with no resistance, save for the annoyed expression on your face. He help up the cup to you. "Ginger ale," he offered. "Here, sit up."

You glared at him, eyeing the cup, then him, then the cup again. Immediately, you pulled out you phone and sent a couple of quick texts before continuing to glare at him again. Sans heard the _ding!_ of a received message and you looked back to open it. You grunted with annoyance, sending back another text (with a bit more vigor this time), before finally groaning and letting your arm flop heavily back to the couch. You looked down at the cup once again as if it had insulted your mother.

"Why are you here?" you asked him. "Come to kick me when I'm down? I'm not in the mood for your games, Sans."

"Your roommate said you had the flu," Sans told you. "Now, sit up. You asked for a drink, so I got you a drink. Here."

"We don't _have_ ginger ale in the house," you growled at him, "I already drank it all."

Sans' smirk widened just a hair. "Then it is a good thing your roommate convinced us to keep some on hand in case Chara showed up sick, isn't it? Now...Sit. Up!"

Grumbling about "pesky skeletons", you pushed yourself up into a sitting position and took the cup from him. You eyed it one more time before locking eyes with him and taking a cautious sip. If you were waiting for a reaction from him, you received none. After all, there were some things that even Sans drew the line at, and one of them was tampering with the food of a sick person. 

Finally, after finding neither reaction nor taste to your dislike, you drained the rest of the cup, clutching your throat and hissing as you finished. Sans took back the offending cup as if yanking a hot iron out of your hand and scowled at it. It was ginger ale! Asgore said that would help you! Why was it making you hurt more?!

He realized he must have spoken some of his thoughts aloud when you waved him off. "It's the carbonation," you told him, your voice raspy from the pain. "It helps with sour stomachs, but man, does it burn on a raw throat. Agh..."

Sans huffed. Healing things that helped some parts of the body but not others? What sort of garbage logic was that?! Your frail human bodies made absolutely no sense to him. It was a wonder your kind ever managed to live long enough to trap monsters Underground in the first place.

It was then Sans got an idea. He looked down at you and pointed a finger in your face. "Do not move. I will be right back," he said before heading off to the kitchen. He washed the cup in the sink and set it aside to dry before digging out a mug from the cupboard. Reaching into the basket he brought, he sorted through the contents, setting everything out in a smorgasbord upon the empty counter. Carefully, he looked over each of the teas, recalling the uses of each one. Half of them were herbal teas, ones that you and your roommate had supplied them with; the other half were far more potent teas, made from a mix of edible materials and magic. 

He picked up the three Monster Teas and looked them over.

The first one was made of some green herbs and the stems and leaves of young Echo Flowers, as well as a flavorful lichen that grew in Waterfall. Inside, Sans knew the dried flora were imbued with green and the tiniest bit of light blue magic - a sedative usually used to calm nerves and soothe those still in stripes.

The second was a more potent batch, made from ingredients around Hotland and little curled shavings of dark chocolate and tidbits of chili. You really loved your spicy teas, and the green magic reacted with the tiniest zap of orange magic in a way that humans had discovered could cure hangovers. However, if your throat was raw, then perhaps it was best he set aside the spicier tea for now.

The third and final tea was one Asgore had sent with Chara as a thank-you present for babysitting them on short notice. It was made from the specially tended golden flowers the Royal Family cultivated, and at one point could hardly be found anywhere besides certain parts of the Ruins and the castle at New Home. Now, however, they were everywhere, and Asgore himself had planted a full flowerbed in the shape of a heart in front of the first Monster Embassy Aboveground — one that was meant to be replanted again and again as visitors, embassy workers, and homeless humans alike came and plucked freely from it, taking the flowers as edible souvenirs. Normally, they provided a warm and almost buttery tasting tea with a flavor that fell somewhere between hazelnut and taro, but with the potent green magic Asgore himself had infused that batch with, it packed enough healing magic in one sip to heal most minor aches and pains almost immediately.

Sans and Papyrus only used that tea for special occasions, wanting to hold out on using all of it just in case they needed some for an emergency.

Well, Sans was no Asgore, so that would have to do until the goat monster arrived.

**Notes for the Chapter:**

> As always, comments are welcomed and appreciated!  
> May whoever is reading this have an awesome day!


	3. CHAPTER THREE - "In Which Fear Nearly Unleashes A Secret"

**Summary for the Chapter:**

> Sans and Reader verbally duke it out over the Battle of the Sport Drinks, and Sans has a moment where his feelings bubble close to the surface.

**Notes for the Chapter:**

> I love and appreciate all of you! thank you for reading and commenting! Just this chapter and one more to go...

**CHAPTER THREE - "In Which Fear Nearly Unleashes A Secret"**  
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You looked just as grumpy when Sans brought you the tea as when he left you. He had planned to hold out the mug to you with his usual proud flourish, but seeing the obvious fatigue weighing your body down dampened his energy. Instead, he gently held the mug out to you, watching the steam rise from the greenish-gold liquid. Thankfully, your curiosity got the better of you, and you thankfully had at least some minor sense of smell remaining.

"What is that?" you said, eyeing the mug.

"Golden Flower Tea," Sans said, "made by Asgore himself."

They perked up at the name. "I know that kind," you said, taking the tea and bringing the cup close where you could enjoy the scent. You closed your eyes and inhaled deeply, letting out a soft sigh of contentment as you took in the smell. It had been a long time since you looked so peaceful and unguarded, so quiet and content. As much as Sans loved to rile you up, he wished he could see such a tranquil expression around him more often. As your tired eyes opened, you stared down at the steaming water with a soft smile, and Sans swore he'd find a way to make you repeat that look without the bags under your eyes or the sickly pallor on your face.

"When did you have Asgore's Golden Flower Tea?" he asked you.

"He brought some as a present when he came to visit us after Papyrus got out of the program," you told him. "He wanted to meet some of the people who he felt were pivotal to his joke buddy's getting his life back on track. I feel like he was mostly doing so to make sure we weren't doing anything to take advantage of the Big Guy. You know," they looked at Sans before taking a sip of the tea, "sort of like you."

Sans could see that. Asgore may have seemed like a pushover, but back in the day, before the Underground went to hell in a handbasket, he had been an insanely powerful monster. Even today, it was still present in his enormous stature. The fur and warm smiles belied the bulk of a former warrior, a true king, one that had helped rule the Underground for many years. With his mind slowly healing and confidence returning, all one had to do was replace the Hawaiian shirts and cutoff slacks Asgore now preferred with the royal robes or armor of old and the picture of the legendary king would be revived. Asgore may not have been able to prevent the strong wills of the human children to keep them from leaving the Ruins, but he had looked out for any monsters in stripes he could find. Sans had heard stories of the feral fallen king and the swift and brutal justice he eked out on anyone who dared tried to harvest what they might of thought was easy LV from monster children under his watch.

 _"Once a father, always a father,"_ Asgore had told him once day after discussing he protectiveness of Chara. Sans supposed that extended just as much to all children of the Underground, too, as well as Asgore's few remaining loved ones. He could very easily see the great king roaring back into his former glory if anyone dared harm one of his friends.

Sans took being compared to the goat boss monster in his revitalized state with pride.

"You think the Great and Malevolent Sans reminds you of Asgore?"

You finished another sip of tea. "A little," you said softly, trying not to stress your throat. You gestured lightly toward the cup. "This is better than I remember it. What did you put in this?"

"Honey," he replied, "something far better for you than the stuff in...these." He gestured down at the platoon of empty soda and sports drink bottles littering the coffee table he had perched himself on.

You huffed at him. "Hey, I'm sick," you told him, "if I want to drink power drinks and sodas, I'll drink power drinks and sodas."

"It's unhealthy," Sans retorted.

"So is throwing up every five minutes for half a week," you retorted, taking another sip of tea. "I needed the electrolytes."

"You don't need _junk food_ ," Sans said, grimacing. 

You glared and set the cup aside on a taller coffee table next to the couch's armrest. "Sans, stop bitching about my drinking habits. It's just sports drinks, and you're acting like my drinking something to stay hydrated when I could barely keep a few crackers down is the same as being, I dunno, an alcoholic." He watched you wipe your hands over your face and run your fingers through your wayward, unkempt hair. It was a gesture you did when you were trying to calm yourself down. 

For once, he hadn't done a thing to rile you up.

Or, so he thought.

"I'm not 'bitching' as you so crudely put it," he told you. "I just know that depriving yourself of good nutrients by choosing a bunch of sugary foods over-"

"Over what, Sans?" you grumbled, your clear frustration causing your tone to rise. "Because that was the only thing that calmed my stomach when I was paying homage to the porcelain throne!" 

"I don't know what this 'porcelain throne' is. I thought your people didn't live under a monarchy?"

You facepalmed, then instantly regretted it - if the groan that followed was anything to go by. "Oww, I shouldn't have done that...me and my freaking puffy face...freaking sinuses," you muttered as you gingerly touched your face. Sans reached out and gently pushed you back so that you were sitting up, then placed a bony hand against your head. You looked like you were halfway to freaking out. "W-wait, what are you doing? Stop," they grabbed hold of his wrist, "let me go!"

"Hush."

Sans tried not to let his gaze linger on your face for more than he had to, lest he be unable to do what he needed to help you. Concentrating, he could feel the green magic bubble up within him, trickling across his chest and down his arm in a winding, bubbling motion. He could feel it collect in his hands before a gentle feeling like popping a bubble zapped against his fingers and palm, and he could feel the magic flow out of him and down into the warm, clammy flesh and soft hair of your head. 

Soon, he cut the magic off and he could feel the magic return to his eyelights. He watched as your now closed eyes gradually opened.

"How do you feel now?" he asked.

You wrinkled your nose and let out a soft grunt, sitting up straight. Blinking, your eyes opened a bit more fully, as much as your fatigue seemed to allow. "My headache...did you...?"

"I'm not very adept at green magic," Sans was loathe to admit, "but I can use it in a pinch. The tea Asgore made has more green magic in one cup than I can normally produce through careful control. You should be feeling a few less aches and pains now, and will feel even less if you finish your tea."

You tested his claim by rolling your shoulders and found that, indeed, some of your achiness had left, and told him so. He nodded and then stood, heading toward the kitchen.

"Where are you going?" they asked. If Sans didn't know any better, he would have swore they sounded almost _disappointed_. But that couldn't be right. No, they just had a burst of energy from the tea. Upon looking back, he could see they were eagerly sipping at the rest of the mug. 

Yeah, just his imagination.

"I am going to make you something that is actually healthy," he said, turning around to pick up a soda bottle and wave it in your face, "so you will have something besides sugary junk food to eat. Now, finish your tea and rest! The great and Malevolent Sans demands it!"

Your protests in defense of your sick-day drinks of choice fell upon deaf ears, as not only did Sans not have those fleshy bits sticking out from the sides of his skull, he also did not care. And perhaps he enjoyed hearing you get riled up a bit now that some of the life had come back into you.

It honestly did not take much time for the soup to heat. He watered down a bit of one of the stocks he brought and threw in a handful of various herbs hehad researched to have healing properties. He thought about adding a pinch or two of the Echo Flower tea, but thought better of it. You needed rest, but he also didn't want to send you into too deep of a sleep before Asgore and Toriel arrived to heal you. He would leave that canister for your roommate to administer to you if necessary, however.

Every now and then, he would hear his phone ping and see a reply from Papyrus. While he had thankfully kept himself from losing his composure in front of you or your roommate, he wasn't able to hide his fears from Papyrus. His brother had informed him how hot to serve the tea and waited on standby as moral support, which he appreciated.

As the soup heated, he checked in on you now and then. Once, he saw you texting on your phone, but you had soon turned on an anime to watch. The sound was turned down fairly low, but Sans could still make out the chipper young female voices and the stereotypical laughter of the villain intermingled between cartoon explosions. It was an easy distraction for you - one that he was thankful for as it allowed him to watch you without giving away his concern.

Eventually, however, his time to pull himself together had run out, and he ladled the thin soup into a bowl for you, adding some crackers to the saucer he placed it on.

You didn't argue with him when he presented you with his offering this time.

He leaned against the back of the couch and pretended to be interested in the anime (one Alphys had already dragged him into a marathon of TWICE), but kept casting furtive glances at you as you stuffed your face. As he watched you nibble a cracker you had dunked into the rich broth, he smiled. You were still sick, but you had regained your appetite somewhat and seemed as happy with his food as a kitten with a dish of cream. And he had been the reason behind that, hadn't he? He shook his head as he saw the bottles of sugary substances littering the table. For someone who tried to be fit and healthy, you certainly didn't do a good job of getting back to that point when sick. You needed someone to make sure you took good care of yourself, made sure you got back to being so full of life.

Who better for the job than the Great and Malevolent Sans?

He spent a few minutes cleaning up the dishes and bottles you had lying around, coming back to see you had put aside his soup after finishing about half of it and the crackers. You had laid back down on the pillow and snuggled down into your blankets.

"Are you going to sleep?" Sans asked as he crouched down next to you. A sleepy little "Uh-huh" came from beneath the blankets pulled up over your nose. Sans nodded, despite your being unable to see through closed eyes. He chuckled and told you to rest away.

As he picked up the bowl and saucer, he heard your voice again, increasingly becoming more and more garbled with impending sleep.

"Sans?" He turned toward you.

"Yes?"

"You know there's no way I can beat you at a healing challenge, so-" they yawned, interrupting their sentence, "-can we just skip the contest and say you won this round?"

He chuckled. "Sure."

"And Sans?"

"Hmm?"

"Thank you."

There were many ways Sans wanted to respond to that:

He wanted to say how it was his pleasure. You deserved it after you helped Papyrus kick his addictions. He could not allow such a worthy opponent to fall to something so unjust and unheroic as the flu. That there was no way he would let anyone or anything hurt you. That he wanted to protect you, even if it meant using up every last ounce of magic within him to pour green magic into your soul, if only it helped you recover. That he had to do something, _anything_ , to wipe that pallor off your face, that seeing how pale and tired you were and how close you might be to dying scared him in a way he hadn't been since he lived Underground. 

That, if he lost you, it might shatter his soul.

Instead, he replied with none of those, merely a nod and a laconic, "You're welcome."

**Notes for the Chapter:**

> All that's left now is the epilogue with more Papyrus & Nameless Nurse Roommate! Stay tuned for that one!  
> Also, how are you all enjoying the depictions I went with for the Fellswap versions of each character? Who's your favorite? And would you like to see any spinoffs using any of them?


	4. EPILOGUE (with Fellswap Papyrus & Nameless Nurse Roommate!)

**Summary for the Chapter:**

> It's the Epilogue!  
> Enjoy!

**EPILOGUE (with Fellswap Papyrus & Nameless Nurse Roommate!)**  
\--------------------------------------

NURSE: BTW, I'm going to be stuck at work for a while, but I sent someone else over to keep an eye on you. Don't worry, you'll like who it is~!

YOU: asdfasfhkj WHY DID YOU SEND SANS OVERHERE!?  
YOU: I asked him to make me a drink thinking it was you! He has a cup with strange liquid in it and is smirking at me!  
YOU: What does cyanide taste like

NURSE: Aww, don't you want to be comforted by the 'Great and Malevolent Sans'? I'm sure he could give you a massage to make you feel better if you asked him to!  
NURSE: Consider it payback for switching my coffee creamer with baby powder. You know I had to show Papyrus that duck  
NURSE: XD He's not going to poison you

YOU: I hate you

SANS: They look bad  
SANS: It is a good thing I called Asgore when I did  
SANS: The ginger ale did not help! How hot do I make the Golden Flower tea?  
PAPYRUS: the same as usual? steep it about ten minutes

YOU: Sans just brought me ginger ale  
NURSE: I know  
YOU: Why did you put him up to this? I'm gonna DIE X-X  
NURSE: You're not going to die, and I didn't put Sans up to it  
YOU: Tell Papyrus to go hug a cactus then  
NURSE: Papyrus says he loves you, too. Also Sans went over there of his own volition. He literally just threw a bunch of stuff in a basket and ported over to you.  
YOU: What? Oh God, what does he have planned?! I'm too sick for this @~@

SANS: And where the hell is Asgore???

PAPYRUS: how are you holding up  
SANS: The tea helped, thank the stars. Also used green magic.  
PAPYRUS: you didnt overdo it did you  
SANS: No  
PAPYRUS: don't lie to me brother  
SANS: I did not lie  
PAPYRUS: sans  
SANS: It was enough to help ease their pains, no more. I will not chance making a mistake when I have two actual healers headed our way.

PAPYRUS: wait when you said you used green magic what did you do  
SANS: I touched them on the head  
PAPYRUS: aww cute  
SANS: Shut up, Papyrus!  
PAPYRUS: was their hair soft  
SANS: ...yes.  
SANS: SHUT IT! I KNOW YOU'RE LAUGHING!  
PAPYRUS: heh

NURSE: How goes it? You haven't killed him, have you?  
YOU: he's makign me  
YOU: soup  
NURSE: He's what?  
YOU: He gave me ginger ale, he made me tea from that special blend Asgore gave us that time, he's only insulted me ONCE, and NOW he's making me soup  
YOU: im dead arent i  
NURSE: OMG XD  
NURSE: THATS SO SWEET  
NURSE: No, you aren't dead  
YOU: I'm either dead or he's planning something  
NURSE: Just hush and enjoy the attention!  
YOU: ...I still hate you. Maybe less, because that tea was freaking delicious  
NURSE: XD

PAPYRUS: hey we fixed bbq nachos you want us to save you any  
SANS: No, I'm fine  
PAPYRUS: how are they  
SANS: Sleeping  
SANS: They weren't coughing as much after the tea. I think it helped.  
SANS: They looked so bad, Papyrus, I thought they were going to fall down  
PAPYRUS: but theyve got you bro  
PAPYRUS: theyre in the best of hands  
SANS: You're right

YOU: YOU DIDNT TELL ME SANS CALLED THE OUT THE ARMY!!!  
NURSE: He didn't call the army. Just Asgore.  
NURSE: If he'd called the army, Alphys would be there  
YOU: OH HAH HAH HAH  
YOU: THE FORMER KING AND QUEEN OF MONSTERS ARE STANDIGN IN MY KITCHEN RIGHT NOW MAKIGN SMALL TALK WITH SANS OVER A FUCKING CUP OF TEA  
YOU: THIS SI SOME ALICE IN WONDERLAND LEVELS OF SHIR RIGHT HERE  
YOU: *photo*  
YOU: I WAS NOT PREPARED FOR THIS  
YOU: I LOOK LIKE S  
YOU: asdjcbvh  
YOU: i dorpped my phone  
NURSE: Sans told us he wasn't good with green healing magic, so he called Asgore. Apparently, Asgore is a really good healer, and Toriel was with him, so she offered to help, too. So lucky!  
YOU: I was literally almost better! I just wanted an extra day off to be lazy and bitch about being sick so I could watch Mew Mew Kissy Cutie!  
NURSE: But you're technically still a little sick with that upper respiratory infection you caught along with it. Or did you forget why you were taking those antibiotics?  
YOU: Well, I'm definitely better now  
NURSE: Still have to finish your meds though  
YOU: I hate you  
YOU: I'm never getting sick again

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Your roommate read the last message aloud, barely able to get the words out through their laughter as Papyrus offered them the plate of BBQ nachos again. 

For the most part, the two lovebirds' text messages had been keeping them and Papyrus entertained most of the day. It eventually got to the point where Papyrus had to actually pause the anime they had been watching because you and Sans had been sending text messages so fast that it was hard for the tall skeleton and the nurse to keep up with what was going on. 

As the nurse scrolled back through their messages to see a still slightly pale you sitting in a selfie with the two former royals and a very smug Sans, they laughed and showed Papyrus the picture. Papyrus chuckled.

"I'm honestly surprised Sans didn't just confess since he thought they were dying."

"Yeah, well," the nurse started, "you've never seen how our little friend acts when they're on cold and flu medicine. It's like they are the sappiest drunken dork you ever did see. I'm actually a bit sad they didn't go all whiny on Sans."

Papyrus took a bite out of a sauce-covered-tortilla chip. "What I'd give you be a fly on the wall for that one."

Grinning, the nurse threw out their arms dramatically and, taking on the tonal inflection of a Southern Belle, cried out, "'Oh, my darling Sans! I've gots the consumption! The only way to heal me is with your loving embrace!'" They put one hand to their forehead, and acted as if they would faint. Papyrus laughed and moved the nachos to the coffee table as the nurse threw their hands up in the air with a melodramatic sigh. "'Catch me, my love!"

They fell back in a fake swoon across Papyrus' lap, nearly elbowing him in the face as he held up a fresh nacho.

"Sorry, toots," he said, trying to keep a straight face, "but these nachos are my only true love."

Instantly, the nurse's eyes snapped open and, with a grin, they nabbed the nacho chip right out of Papyrus' fingers and popped it in their mouth, hopping back up into a sitting position with the biggest closed-mouthed smirk they could muster. Papyrus let out a noise of protest, only to get a chuckle for his efforts.

It was silent for approximately ten seconds before the two of them burst into raucous laughter.

Yeah, hanging out with Papyrus and binging on BBQ nachos while reading your texted freak outs was a much better way to spend the day than rewatching "Mew Mew Kissy Cutie" for the eighteenth time!

**Notes for the Chapter:**

> We have now reached the end of this story.  
> I hope you all enjoyed as much as I love writing it, because once I got started, I couldn't put it away for long. This was a blast to write and I hope you loved reading our two emotionally constipated tsunderes lose their minds this time around.
> 
> So, what did you all think? Be sure to let me know in the comments below.  
> If anyone has any suggestions for drabbles they'd like to see or podfics they'd like to hear, then by all means, let me know.
> 
> Thank you all so much for reading and all your lovely comments. I wouldn't have done more than the one-shot that started this series without your support, so it makes me feel pretty good to see people still enjoy my writing even after I've gone so long without posting much anywhere. You all have a wonderful day! I'm out!

**Author's Note:**

> Don't forget to comment so you can leave your feedback!  
> Commenters may randomly be gifted stories (as part of this series has proven) ^-^


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